Drug & supplement interaction

Basil + Fondaparinux

Fondaparinux brand name: Arixtra.

Moderate Interaction
The bottom line Moderate

Basil has a moderate interaction with Fondaparinux. Theoretically, basil might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Basil and Fondaparinux

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Fondaparinux

Fondaparinux falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Basil interacts with.

Theoretically, basil might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro and animal studies suggest that basil oils and extracts inhibit platelet aggregation.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the basic idea with basil and fondaparinux (Arixtra). Fondaparinux is already a powerful blood thinner that lowers your blood's ability to clot. In lab dishes and animal studies, concentrated basil oils and extracts have shown a mild tendency to make platelets (the cells that help form clots) stickier and slower to clump together. Stack that on top of fondaparinux and, in theory, you could bleed a little more easily.

I want to keep this in perspective, though. This concern comes only from test-tube and animal work, not from people, so it's theoretical. The basil you sprinkle on pasta or pizza is very unlikely to matter. Concentrated basil supplements or essential oils are the real question mark. Watch for easy bruising, nosebleeds, or bleeding gums, and check with your pharmacist or doctor before adding any basil product.

References
  1. Tognolini, M., Barocelli, E., Ballabeni, V., Bruni, R., Bianchi, A., Chiavarini, M., and Impicciatore, M. Comparative screening of plant essential oils: phenylpropanoid moiety as basic core for antiplatelet activity. Life Sci. 2-23-2006;78(13):1419-1432. PubMed
  2. Tohti, I., Tursun, M., Umar, A., Turdi, S., Imin, H., and Moore, N. Aqueous extracts of Ocimum basilicum L. (sweet basil) decrease platelet aggregation induced by ADP and thrombin in vitro and rats arterio--venous shunt thrombosis in vivo. Thromb.Res 200 PubMed
  3. Amrani, S., Harnafi, H., Gadi, D., Mekhfi, H., Legssyer, A., Aziz, M., Martin-Nizard, F., and Bosca, L. Vasorelaxant and anti-platelet aggregation effects of aqueous Ocimum basilicum extract. J Ethnopharmacol. 8-17-2009;125(1):157-162. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Basil Also Interacts With Other Medications

Basil has 288 moderate known drug interactions in our database — the Fondaparinux one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Basil

Covers the 2,830 medications we’ve checked against Basil. Pick one to open its full report.

From our Q&A

Questions About Basil or Fondaparinux

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Basil or Fondaparinux, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Fondaparinux

This page covers Basil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fondaparinux page lists 202 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Danshen (major), Piracetam (major), Aconite (moderate), Allspice (moderate) and Aloe (moderate).

By severity: 2 major · 183 moderate · 17 minor.

From our pharmacist’s overview on the Fondaparinux page

“Most people on fondaparinux (Arixtra) are recovering from surgery or treating a blood clot, exactly the moment supplements for circulation and recovery come out of the cabinet. This pairing deserves real care, because nearly all 202 ingredients on this list share one problem: they thin the blood a little on their own, so adding them to…”

Reviewed by 2 · Jul 18, 2026

Open the Fondaparinux interaction page

One more smart check

Taking Basil as Part of a Dietary Supplement Product? Check It for Interactions

We hold 396 real supplement products containing Basil, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Basil. Your product may carry other ingredients that interact with Fondaparinux too, on top of Basil — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Basil and Fondaparinux Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Basil
Top 25%

#334 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Fondaparinux
Top 10%

#239 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Basil

What is Basil?

Basil
  • Digestive upset and gas
  • Stress and anxiety
  • Antimicrobial support
  • Cold and cough symptoms
  • Headache
  • General antioxidant support

Basil is a popular cooking herb that is generally safe in the amounts used in food. While it has a long history of traditional medicinal use and contains antioxidant compounds, strong human evidence for most health claims is limited. Talk with your pharmacist or doctor before using concentrated supplements or essential oils.

Read the full Basil monograph & all interactions
Medication

About Fondaparinux Injection

What Is Fondaparinux Injection Used For?

Brand name: Arixtra

Fondaparinux sodium injection is used to prevent deep vein thrombosis (DVT) — blood clots that form in the legs — in adults who are having hip fracture surgery, hip replacement surgery, knee replacement surgery, or abdominal surgery. Preventing these clots also lowers the risk of a clot traveling to the lungs (pulmonary embolism, or PE).

It is also used to treat acute DVT and acute pulmonary embolism in adults, typically started alongside warfarin. In children aged 1 year and older who weigh at least 10 kg (about 22 lbs), fondaparinux sodium injection is approved to treat venous thromboembolism (VTE) — blood clots in the veins.

See full Fondaparinux Injection drug information
Keep checking

Other Drugs & Basil

Browse every other medication we’ve checked against Basil — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
288Moderate
0Minor
2,541No known interaction
Moderate

288 interactions

Showing 60 of 288 moderate interactions — see all 288 on the Basil page.

No interaction 2,541 drugs checked — show the list
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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Pharmacist Counseling Corner

Taking Basil and Fondaparinux Together: Common Questions

Can you take Basil with Fondaparinux?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Basil and Fondaparinux interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Fondaparinux and Basil?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.